CODEWITHSUNDEEP
csegmentation-faultdescrypt
Jasmeet Singh
Jasmeet Singh

Reputation: 25

Segmentation Fault in C while using crypt function

I am new to programming in C.I am trying to make a simple password cracking program but when I try to run it I get Segmentation Fault as an error. Can someone solve the issue. Thanks in advance.

#define _XOPEN_SOURCE
#include<stdio.h>
#include<crypt.h>
#include<unistd.h>
#include<string.h>

int main(int argc, char *argv[])
{
    if(argc != 3)
    {
        printf("Usage: ./craken salt hash\n");
        return 0;       
    }


    FILE *fPointer;
    fPointer = fopen("wordlist.txt", "r");

    char singleLine[150];
    while(fgets(singleLine, 150, fPointer) != NULL)
    {   
        if(!strcmp(argv[2], crypt(singleLine, argv[1])))
       {
            printf("Password found! %s is the password\n", singleLine);
            fclose(fPointer);
            return 0;
       }
    }
    printf("Not found\n");
    fclose(fPointer);
    return 0;
}

Upvotes: 0

Views: 582

Answers (1)

jotschio
jotschio

Reputation: 11

I guess the problem is that if you read out possible passwords out of you're file there is an newline at the end. The crypt() function as I understand can only handle the set [a-zA-Z0-9./] (crypt man page) that might result in an NULL pointer being returned. This NULL pointer than leads to a segmentation fault inside the strcmp() function. So try to remove that newline char at the end of each input line. Hope this works

Upvotes: 1

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